Oder or Aider: How To spell?

The word Oder is misspelled against Aider, a noun meaning "One who, or that which, aids."

Word begins with consecutive vowels 'AI' followed by alphabets 'der' is misspelled as 'O'
Wrong Spelling:  o-der 
Correct Spelling:  ai-der 
Explore spell check of Aider to spell without errors.

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